A Long Term Evolution (LTE) system, a Long Term Evolution-Advanced (LTE-A) system, an International Mobile Telecommunication Advanced (IMT-Advanced) system are all based on the technique of Orthogonal Frequency Division Multiplexing (OFDM). A time-frequency two-dimensional data form is mainly adopted in the OFDM system. In the LTE and the LTE-A, a Resource Block (RB, when the RB is mapped on to the physical resource, the RB is called a Physical Resource Block (PRB)) is defined as OFDM symbols inside a slot on a time domain, and 12 or 24 subcarriers on a frequency domain, so that one RB consists of Nsymb×NscRB resource elements (RE), wherein the Nsymb indicates the number of the OFDM symbols inside one slot, and NscRB indicates the number of subcarriers occupied by the RB on the frequency domain. That is to say, the resource block refers to a plurality of subcarriers (for example, 12 subcarriers) occupied in the frequency direction and all OFDM symbols occupied inside one slot in the time direction; and a resource block pair refers to a pair of resource blocks corresponding to two slots in one subframe (in the frame structure shown in FIG. 2, a wireless frame comprises ten subframes, and each subframe comprises 2 slots. In the case of normal cyclic prefix, one slot comprises seven OFDM symbols, and in the case of extended cyclic prefix, one slot comprises six OFDM symbols).
Moreover, the concept of resource block group is also defined in the system, that is, a plurality of continuous resource blocks forms a resource block group. The size of the resource block group is determined by the system bandwidth. For example, when the system bandwidth is less than or equals to ten resource blocks, the resource block group comprises 1 resource block. For another example, when the system bandwidth is 11 to 26 resource blocks, the resource block group consists of 2 resource blocks. For another example, when the system bandwidth is 27 to 63 resource blocks, the resource block group consists of three resource blocks; and when the system bandwidth is 64 to 110 resource blocks, the resource block group consists of four resource blocks.
In the LTE-A system, a new link is added after the Relay Node (RN) is introduced, as is shown in FIG. 1, the link between an eNode-B and a relay is called a backhaul link or relay link; the link between the relay and the User Equipment (UE) is called an access link; and the link between the eNode-B and the UE is called a direct link.
At present, it is a hotspot, in the LTE-A system, of researching the multiplex mode between a control channel and a traffic channel after a relay node is introduced, for example, Time Division Multiplex (TDM), Frequency Division Multiplex (FDM), and FDM+TDM are adopted for multiplexing. However, the research on resource allocation for R-PDSCH has not been developed, which is the problem the present disclosure aims to solve. Wherein
TDM refers to that the Relay link-Physical Downlink Control Channel (R-PDCCH) and R-PDSCH are transmitted in different OFDM symbols;
FDM refers to that the R-PDCCH and the R-PDSCH are transmitted in different PRBs;
FDM+TDM refers to that the R-PDCCH and the R-PDSCH are transmitted in identical or different PRBs.
A PDCCH includes at least DL grant and UL grant. For PDCCH, the DL grant and the UL grant are carried on the first, the first two, the first three or the first four OFDM symbols of the first slot, and occupy the whole system bandwidth in the frequency direction. For R-PDCCH, the DL grant is carried on the available OFDM symbols of the first slot, the UL grant is carried on the available OFDM symbols of the second slot, and the DL grant and the UL grant occupy a plurality of resource blocks in the frequency direction, and the occupied maximal band width can be up to the whole system bandwidth.
So far, there has not been proposed a mapping and resource allocation method for R-PDSCH.